Though this year's tornado season in
Georgia was not as active as the past few years, researchers at Georgia
Tech are busy analyzing the weather data they collected from several
twisters that hit the state this past spring. They hope this
information will help them improve current storm detection technology,
while they also create new methods to increase warning time.

Researchers at the Severe Storms Research
Center (SSRC) at Georgia Tech completed their first tornado season
since installing three state-of-the-art Warning Decision Support
Systems (WDSS) in metro Atlanta early this year – two at Georgia Tech
and one at the National Weather Service
office in Peachtree City, Ga. Researchers are using these systems to
determine if the WDSS tornado recognition logic can be better "tuned"
to the tornadoes of the Southeast.

"Tornadoes in Georgia and
elsewhere in the Southeast are often short-lived events," says Gene
Greneker, director of the SSRC. "Here, tornadoes can come and go in 10
minutes, as opposed to an hour in Kansas."

WDSS technology – which
includes advanced image processing, artificial intelligence, neural
networks and other algorithms that use Doppler radar data – was
developed at the National Severe Storms Laboratory
in Norman, Okla. There, studies showed a 50 percent increase in warning
time for tornadoes, severe thunderstorms and flash floods in Great
Plains states.

"Another goal of the SSRC
is to fund the development of new technologies that may be able to
detect the early formation of tornadoes," Greneker says. "If we are
successful, these technologies could complement the Doppler radars
operated by the National Weather Service."

Complementary technologies being developed by Georgia Tech researchers are:

early detection of tornadoes based on the "acoustic signatures" they
produce and on the correlation between tornado occurrence and pre-storm
thunder activity. Dr. Krishan Ahuja, a professor of aerospace
engineering and a Regents Researcher at Georgia Tech Research Institute
(GTRI), is trying to determine whether there is a correlation between
tornado sound and the rotational speed of tornadoes as they
materialize. If so, researchers could determine an "acoustic signature"
that would predict tornadoes before they actually form.

early detection of tornadoes based on a pattern of increasing
electrical discharges produced by cloud-to-cloud lightning strikes. Dr.
Tom Pratt, a senior research engineer at GTRI, has developed a
first-generation lightning detection system that provides range,
direction and radio frequency signatures associated with lightning
activity in severe thunderstorms. He plans to fine tune the system by
integrating additional sensors, including acoustic devices, into the
system, and by developing advanced processing and analysis capabilities
to improve total lightning detection and discrimination.

a more meaningful 3-D severe thunderstorm display that is designed with
human perception capabilities in mind. GTRI principal research
scientist Nick Faust has created an integrated visualization of 3-D
Doppler radar and global, high-resolution terrain – representing the
first time such data have been displayed together in real time. This
system also provides integrated browsing and analysis, and integration
of relevant data, such as buildings and maps. The latter capability
will grow in importance as researchers develop sophisticated models of
storm development that yield rules for how storms behave in the
presence of hills or mountains and other features, Faust reports.

high-resolution documentation of tornado tracks based on storm path and
duration information gathered at the scene. Research scientist Dr. Jim
St. John, of the School of Earth and Atmospheric Sciences, is creating
a detailed database called the Tornado Track Survey. The database
contains tornado start and end points, as well as detailed descriptions
of damage caused by the storm. St. John uses global positioning system
receivers to pinpoint locations along the storm track, and he shoots
digital images to record damage at each point. This information is then
available to other researchers for comparison to radar or other data to
investigate characteristics and evolution of tornadoes.

more effective tornado detection algorithms than are currently part of
WDSS. Principal research engineer Dr. Mark Richards and senior research
engineer Vince Sylvester, both of GTRI, want to make radar smarter
using advanced signal processing techniques. These will clarify the
system's often-indistinct display of a tornado's rotating wind pattern.
The researchers are also applying new target recognition methods to
detect tornadoes and their precursors. In addition, they are studying
potential sites for an experimental radar station in north Georgia,
parts of which are underserved by existing stations, the researchers
say.

"While these technologies are experimental, they are promising," Greneker says. "They will continue to be tested."

After the WDSS technology has been tested in north Georgia, it will be
exported to south Georgia as funding permits, Greneker says.

The SSRC's research is
being funded by the Georgia Emergency Management Agency, the Federal
Emergency Management Agency, the Georgia General Assembly and a grant
from BellSouth Business Systems.